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POPULAR SCIENCE MONTHLY.
prevails. Here are a few of the obstacles to be encountered. As the table indicates, the countries north of the Alps have been mainly studied through their school children. In the Latin half
of Europe adults alone are included. Secondly, it is a matter of common observation that flaxen hair and blue eyes are characteristic of childhood. As it has been proved that from ten to twenty per cent of such blond children at maturity develop darker hair
